Improvement in sewing-machine



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'WILLIAM C. WILLMARTH, 0F PHlLADEIiPHIA,PENNSYLVANIA, SSIGNOI.. TO `B. W. LACY AND S. '0. EATON, 0F SAME PLACE.

i Lettere' Patent Ne. aose, dated August 11,1868;

IMPROVEMENT IN SEWING-MACHINE.

To AALL ,WHOM IT MAY' columnar; i

Be it known that I, WIILIAM C. WILLMARTH, ot' Philadelphia, Pennsylvania, have invented an Improvement in Sewing-Machines; and I do hereby declare the following to be a full, clear, and exact description of the samev My invention consists of certain sewing-mechanism, constructed and operating as fully described hereafter, so as to producenJ chain-stitch.

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe vits construction and operation, reference being had to the accompanying Adrawing, which forms a part ofthis specification, and in which- Figure 1 is a sideelevation of my improved sewing-machine.

Figure 2, a front elevation, partly in section.

Figure 3, an inverted plan View; and

Figures 4 and 5 vdetached views of parts of the machine, showing the said parts in diii'erent positions.

.Tothe upper side of the baise-plalt'eji`-A is secured the usual stationary arm, B, in which turns a shaft, C; and to the rear end' of the latter is seeureda grooved pulley, D, atene side of which-is a cam, E.

On the lower side of the base-plate is an arm, F, at the front side of which are two projections, a. i12-and through the latter passes a vertical vthumb-screw, G. 4

On a pin on the arm F turns a grooved drivingpulley, II, round which, and round' the pulley D, passes the band 6. Y

At one side of the stationary arm B, near the frontend vof the same, is a projecting rib, c, which vextends through a slot in an adjustable plate, I, and to the side ofthe latter is' hunga cam-lever, J, which bears onlthe upper end of the projection e, so that the plate maybe elevated or depressed by turning the said lever. A spring, d, secured to the arm B, and bearing on the plate I, tends. to maintain the latter at the limit oi' its down- .ward motion. vThe lower end ofthe plate I` is bent to one side, so as to form a presser-foot, e, which rests on a work-plate, J', secured to the base-plateA, and in the centre of the presser-foot is a' slot, e', which is directly abevea slot, t', in thev work-plate. l' i To the front end of the shaft C is secured a disk, K, to which is hung loosely an arm, L, and in a socket at the lower end 4of the latter it's the'shank of a detachable eye-pointed needle, u, which is secured by a setscrew, 7c. i

The lower end of theneedle n passes through a slot, m, in an adjustable plate, I', secured to the plate I,

`the said plate I being in such a position that the needle canno't be withdrawn from the opening m without first detaehing it from the arm L.

To the arm B is secured a tension-device, M, which consists of a tapering pin, v,turning in a projection, l w, there being anopening in the head of the pin for the' passage of the needle-thread which is carried by aV spool, X, turning on a rod projecting from the arm B. l

In a projection, Bl', at the front end of the arm B, is an opening, ze', and to the arm B, at the rear of the said projection, is secured a rod, N, in`,the upper end of which is a recess, x2, a washer, p, resting on a spring, o, coiled round the said rod. y

To the under side of the plate A is hung a lever, O, into a slot in the rear end of which projects the lower end oi' a lever, P, hung` to the arm B, the upper end of the said lever bearing against the cam E.

To the front end of the lever O is jointed a plate, Q, at one side of which are a pointed projection, g, and

' an arm, g; and to the lever O is secured a spring, r, one end of which bears against the arm F, and the other against a pin on the plate Q, the spring tending to maintain the lever and plate,in the position shown in fig. 3. To the under side of the work-plate J is secured an adjustable plate, R, on which are two projections, tu,

the latter being adjacent and parallel' to the slot z' in the work-plate. i

The machine is seciired to a table or stand, Y, the edge of which is clamped between the projection a and the screw G, as shown in iig. 1. The' fabric to be sewed' is placed beneathv the presser-foot, on the work-plate l the thread :c is passed to the tension-device M, through thc slot in in the rod N, through the opening ml in the projection B', and through the eyeV of the needle. The parts are` brought to the position shown in iigs. 1, 2, and 3, and a. rotary motion in the direction of its arrow is imparted to the driving-wheel H.

- As the disk K revolves inthe direction of its arrow, the needle n will be carried towards the outer end of the slot m', and will enter the fabricnear 'one end of the slotz'. As the revolution ofthe disk K is continued, the

needle (bearing against the yendof the slot mjwill be moved to the positionshown in red lines, iig. 2\, `the lower -portion of the needlebeing thus caused to traverse the slot z', and the fabric being moved by 'the needle in the direction of the arrow 2, Bg.' 2. I y

As the needle begins to ascend, a loop of thread, will be formed at the 'side of the saine, opposite the projection u. The lever O will then move in the directionA of its arrow, g.' 3, 'and the projection q will catch and carry the loop of thread to the position shown in fig. 4.

The needle will now rise and take the position shownin iig. -2, prior to again descending, while the lever 0 will move still further. in Athe direction of its arrow, the arm g of the` plate Q will strike the projection t, and the plate `will be turned to the. position shown in g.'.5, the loop of thread being thus carried to such a position that it will be penetrated by the needle as it again-descends.

The lever now moves back to its `first position, (the projection q discngaging itself from the loop,) the needle begins `to ascend, and another loop is formed at the side of the same, and-is caught by the projectionq in the same manner as the first, an ordinary chain-stitch being thus produced.' A y By raising or lowering theplate I, the extent oi the needles vibration may be increased or diminished, so as to regulate the size of the stitch'. i v

The projection u insures the formation of the loop of thread at the side, where it will be seized by the projection g. ,A I

The tension upon the thread (during the Adownward movement of the needle) is such that the spring ois compressed, the thread sliding towards the lower end of the slot 222.* When, however, the'V needle beginsl to ascend, the spring will rise,.and by taking up the thread, prevents the loop from forming too near the point of the-needle to be caught by the projection g.

. I claim as my invention, and desire. to secure by Letters Patenty The revolving disk K, arm L, carrying a detachable needlekn'a'nd the adjustable 'slotted plate I', i-n combination with the vibrating lever O, its plate Q, projection g, and the adjustable sto-p t, the whole being constructed andoperating 'as and for the purpose described.

In testimony whereof, I have signed my nameto this specification in the presence of two subscribing witnesses.v

, W. C. WILLMARTI-I. Witnesses: JonN WHITE,

CHARLES E. FOSTER. 

